feature #21037 [WebLink] Add class to parse Link headers from HTTP responses (javiereguiluz)

This PR was squashed before being merged into the 7.4 branch.

Discussion
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[WebLink] Add class to parse Link headers from HTTP responses

Fixes #21005.

Commits
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d7fd599 [WebLink] Add class to parse Link headers from HTTP responses

Author: OskarStark

web_link.rst

@@ -195,6 +195,30 @@ You can also add links to the HTTP response directly from controllers and servic
         }
     }
 
+Parsing Link Headers
+--------------------
+
+Some third-party APIs provide resources such as pagination URLs using the
+``Link`` HTTP header. The WebLink component provides the
+:class:`Symfony\\Component\\WebLink\\HttpHeaderParser` utility class to parse
+those headers and transform them into :class:`Symfony\\Component\\WebLink\\Link`
+instances::
+
+    use Symfony\Component\WebLink\HttpHeaderParser;
+
+    $parser = new HttpHeaderParser();
+    // get the value of the Link header from the Request
+    $linkHeader = '</foo.css>; rel="prerender",</bar.otf>; rel="dns-prefetch"; pr="0.7",</baz.js>; rel="preload"; as="script"';
+
+    $links = $parser->parse($linkHeader)->getLinks();
+    $links[0]->getRels();       // ['prerender']
+    $links[1]->getAttributes(); // ['pr' => '0.7']
+    $links[2]->getHref();       // '/baz.js'
+
+.. versionadded:: 7.4
+
+    The ``HttpHeaderParser`` class was introduced in Symfony 7.4.
+
 .. _`WebLink`: https://github.com/symfony/web-link
 .. _`HTTP/2 Server Push`: https://tools.ietf.org/html/rfc7540#section-8.2
 .. _`Resource Hints`: https://www.w3.org/TR/resource-hints/